Field of the Invention
The present invention relates to a door frame for a vehicle having improved anti-corrosive performance, and a method of manufacturing the door frame, and more particularly, to a door frame for a vehicle, which includes a sealer between steel plate layers of the door frame, and a curved portion, thereby improving anti-corrosive performance of the door frame for a vehicle, and a method of manufacturing the door frame.
Description of Related Art
In a vehicle, a door is classified into a frame type door, a frameless type door, and a full door type door, the frame type door among the doors has excellent characteristics in that sealing between the door and a body is excellent, thereby preventing noise and water leakage.
The frame type door is a door frame 10 for a vehicle as described in FIG. 1, and generally manufactured by a roll forming process, and a cross section taken along line A-A′ of the manufactured door frame for a vehicle has a structure in which steel plates are superimposed as illustrated in FIG. 2.
In particular, in the case of a three-stage superimposed portion 30 in which three sheets of steel plate layers such as an upper steel plate layer 20, an intermediate steel plate layer 21, and a lower steel plate layer 22 are superimposed based on the A-A′ cross section, electrodeposition coating is performed after completion of a roll forming process in order to improve anti-corrosive performance of the door frame. However, although the electrodeposition coating is performed, an electrodeposition liquid does not easily flow into the three-stage superimposed portion 30, and as a result, corrosion may easily occur in the three-stage superimposed portion 30 of the door frame 10 for a vehicle due to inflow of moisture or the like when the door frame 10 for a vehicle is actually used.
In order to solve the aforementioned problem with corrosion, a method of precisely applying a sealer outside the superimposed portion of the formed door frame has been developed, but there is a problem in that costs are high, such that economic efficiency deteriorates.
Otherwise, the door frame has been manufactured by using a deviation plating steel plate as a high corrosion resistant anti-corrosive steel plate, but costs are also excessively increased, and as a result, there is difficulty in commercial availability.
Accordingly, the present inventor intends to develop a door frame for a vehicle and a method of manufacturing the door frame which may minimize an increase in costs, and may improve anti-corrosive performance.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.